System for maintaining integrity of a dry pipe system with heated cabinet and flow restrictor valve

ABSTRACT

A system and method for maintaining the integrity of a dry pipe sprinkler system. The system can includes an auxiliary drain including a main collection pipe, a heater having a bracket configured to attach the heater to the main collection pipe of the auxiliary drain, the bracket including a deflector configured to direct heat from the heater onto the main collection pipe, and a self-draining apparatus configured to receive excess water from the auxiliary drain.

FIELD OF DISCLOSURE

The present disclosure generally relates to dry pipe sprinkler systemsor pre-action systems and in particular to a system for maintainingintegrity of a dry pipe system in a heated cabinet with a mechanicaldrain trap and a Y-strainer, or a programmable logic controller withautomatic valves, and an optional a flow restrictor valve.

BACKGROUND

A dry pipe sprinkler system or pre-action system comprises a firesuppression system that is typically used in structures and areas thatare oftentimes unheated and subject to freezing temperatures. The drypipe sprinkler system includes a network of pipes including branch linesservicing sprinkler heads, risers, and feed mains for delivering waterfrom a water supply to the branch lines. Under normal conditions, thisnetwork of pipes contains a pressurized gas, such as air or nitrogen,which holds closed a dry pipe valve that connects the main supply pipesof main feeds of the sprinkler system to the water supply. When heatfrom a fire opens a sprinkler, the compressed gas is released from thesystem. The resulting drop in pressure causes the dry pipe valve toopen, or trip, thereby releasing water into the main supply lines ormain feeds.

When the network of pipes is filled with the pressurized gas and theambient temperature lowers, condensate can collect in the network ofpipes. If the condensate builds up in the system, then there is a riskthat the condensate will freeze in the pipes. Freezing condensate cancause pipes to leak or burst, or inhibit the flow of water through thebranch lines in the event of fire. For this reason, dry pipe systemsoften include one or more condensate collector arrangements (sometimescalled an “auxiliary drain”) which collect condensate from the networkof pipes. These auxiliary drains are typically located at low points ofthe dry pipe system and usually include a drainage valve and a shut-offvalve connecting the auxiliary drain to a low point. An auxiliary drainis drained of condensate by first closing the upper valve. This preventspressurized gas from exiting the system when the auxiliary drain isbeing drained. The drain valve is then opened and condensate is drainedfrom the auxiliary drain. Then the drain valve is closed again and theupper valve is reopened to again allow condensate to be collected.

A fully open or ruptured auxiliary drain will allow the compressed airinside of the dry system to rapidly vent. This will falsely trip the dryvalve, allowing pressurized water to enter the dry portion of the systemand a potentially damaging high flowrate will spill out of theopen/broken auxiliary drain. In addition to occupant inconvenience, acompromised auxiliary drain can result in thousands of dollars in damageand repair costs plus, hours of maintenance/service time to restore thesystem to normal operation.

U.S. Patent Application Publication No. 2014/0060652 discloses anassembly having an auxiliary drain with a level switch, housed in aninsulated cabinet with a heater. The heater monitors the temperature inthe cabinet and turns on and off as needed to keep the accumulatedcondensation in the auxiliary drain from freezing. When the amount ofwater collected reaches a certain volume the level switch will activateand an audible and/or visual alert can be given that the auxiliary drainneeds attention.

One of the factors working against an automatically draining auxiliarydrain is the fact that building code currently requires that the outletof an auxiliary drain terminate in either a cap or a plug. Typically,auxiliary drains have been located throughout a structure with littleconcern for incorporated draining, basically a maintenance worker goesaround with a bucket or if temperatures are warm enough just dumps thecontents of the auxiliary drain out onto the floor of the structure,giving a distinct rust color staining on the floor and walls near theauxiliary drain. However, as systems become more sophisticated and thedesire for automation increases, it is anticipated that relevantbuilding codes will be altered or Authority Having Jurisdiction's(AHJ's) will allow auto draining as long as accommodations have beenmade to drain the water safely so as not to cause a potentialslip-and-fall situation.

BRIEF SUMMARY

In accordance with the above, it would be desirable to have a system formaintaining integrity of a dry pipe system in a heated cabinet with amechanical drain trap and a Y-strainer, or a programmable logiccontroller with an automatic valve, and an optional a flow restrictorvalve.

In accordance with an aspect, a system is disclosed for maintaining theintegrity of a dry pipe sprinkler system, comprising: an auxiliary drainincluding a main collection pipe; a heater having a bracket configuredto attach the heater to the main collection pipe of the auxiliary drain,the bracket including a deflector configured to direct heat from theheater onto the main collection pipe; and a self-draining apparatusconfigured to receive excess water from the auxiliary drain.

In accordance with another aspect, the self-draining apparatus includes:a Y-strainer in communication with a side port of an upper portion ofthe auxiliary drain, the Y-strainer configure to receive the excesswater from the main collection pipe of the auxiliary drain; a drain traparranged in parallel to the auxiliary drain and in communication withthe Y-strainer, the drain trap having a float configured to releasewater from the drain trap upon the float lifting off a seat within thedrain trap; and a drain tube extending from a lower portion of the draintrap and configured to receive the water released from the drain trap.

In accordance with an aspect, the self-draining apparatus includes aprogrammable logic controller configured to receive a signal from alevel switch within the auxiliary drain when the excess water isdetected in the main collection pipe of the auxiliary drain; and anautomatic drain on a lower portion of the auxiliary drain, the automaticdrain including a plurality of valves, each of the plurality of valvesconfigured to receive signal from the programmable logic controller torelease at least a portion of the excess water within the auxiliarydrain though a drain pipe connected to the automatic drain.

In accordance with another aspect, a flow restrictor valve is disclosed,the flow restrictor valve comprising: a plunger configured to be held inan open position by a compression spring, the open position configuredto allow a liquid or gas to flow through the flow restrictor valve and aclosed position in which a flow of the liquid or gas generates avelocity sufficient to cause the compression spring to compress andengage an outer edge of the plunger with a seat of a retaining member toprevent the flow of the liquid or gas through the flow restrictor valve.

In accordance with a further aspect, a method is disclosed formaintaining the integrity of a dry pipe sprinkler system, comprising:providing an auxiliary drain including a main collection pipe; attachinga heater having a bracket to the main collection pipe of the auxiliarydrain, the bracket including a deflector configured to direct heat fromthe heater onto the main collection pipe; and releasing excess waterfrom the auxiliary drain with a self-draining apparatus, theself-draining apparatus configured to receive the excess water from theauxiliary drain

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of an auxiliary drain and/or condensatecollecting system in accordance with an embodiment disclosed here.

FIG. 2A is a top view of the cabinet for the auxiliary drain and/orcondensate collecting system as shown in FIG. 1.

FIG. 2B is a front view of the cabinet for the auxiliary drain and/orcondensate collecting system as shown in FIG. 1 with the door closed.

FIG. 2C is a side view of the cabinet for the auxiliary drain and/orcondensate collecting system as shown in FIG. 1.

FIG. 3 is front view of the housing for the auxiliary drain and/orcondensate collecting system as shown in FIG. 1 with the door open inaccordance with another embodiment.

FIG. 4 is an illustration of a dry pipe sprinkler system in accordancewith an embodiment.

FIG. 5A is a front view of the auxiliary drain in accordance with anexemplary embodiment.

FIG. 5B is a side view of the auxiliary drain as shown in FIG. 5A.

FIG. 6 is a cross sectional view of the first valve and the flowrestrictor valve along the line VI-VI in FIG. 5A.

FIG. 7A is a top view of a flow restrictor valve in accordance with anembodiment.

FIG. 7B is a side view of the flow restrictor valve.

FIG. 7C is a bottom view of the flow restrictor valve.

FIG. 8 is a cross sectional view of the flow restrictor valve along theline VIII-VIII in FIG. 7B in an open position.

FIG. 9 is a cross sectional view of the flow restrictor valve along theline IX-IX in FIG. 7A in a closed position.

FIG. 10 is a detailed sectional view of the section X of FIG. 9.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Set forth below with reference to the accompanying drawings is adetailed description of embodiments of a system for maintainingintegrity of a dry pipe system in a heated cabinet with a mechanicaldrain trap and a Y-strainer, or a programmable logic controller withautomatic valves, and an optional flow restrictor valve and representingexamples of the disclosed system for maintaining integrity of a dry pipesystem in the heated cabinet with the mechanical drain trap and theY-strainer, the programmable logic controller with the automatic valves,and the flow restrictor valve.

In accordance with an exemplary embodiment, an auxiliary drain and/orcondensate collecting system 100 is disclosed that can be either fullyor semi-automated, and can reduce the possibility of human errorinherent with the unskilled maintenance personnel typically tasked withmaintaining the auxiliary drains. With current commodity type auxiliarydrains there is no way of knowing how much condensation has accumulatedand the drains lack the ability to alert personnel of their status andtherefore to prevent freezing they require constant attention.

FIG. 1 is a front view of an auxiliary drain and/or condensatecollecting system 100 in accordance with an embodiment disclosed here.FIGS. 2A, 2B, and 2C are a top view, a front view, and a side view ofthe cabinet 102 for the auxiliary drain and/or condensate collectingsystem 100 as shown in FIG. 1. As shown in FIGS. 1, 2A, 2B, and 2C, thesystem 100 includes a cabinet 102 comprised of a housing 110 with a door112 hinged, for example, on a piano hinge 114. In accordance with anexemplary embodiment, the housing 110 is configured to house anauxiliary drain 120, a heater 130 having a deflector plate 132, and aself-draining apparatus, for example, a mechanical drain trap 140, asecond drain line (i.e., drain tube) 150, a Y-strainer 160, and anelectrical enclosure 170.

The housing 110 and the door 112 may be made of steel and may beinsulated with a foil faced foam board insulation to help retain heat.In accordance with an embodiment, the insulation has a thickness, forexample, of ¼ inch to ¾ inch, for example ½ inch. The housing 110 mayinclude a plurality of tabs 220, 222, 224, 226 (FIG. 2B) for mountingthe housing 110 upon a concrete pillar, wall or other surface as may bedesired or required. The door 112 can include a key lock 139 (FIG. 2B)and attendant latch 138 on the inside of door 112.

Within housing 110, the auxiliary drain 120 can be mounted to housing110, for example, with a pair of U-bolts. Extending from the top ofhousing 110 is input pipe 123, which is connected in turn to a dry pipesprinkler system (FIG. 4). Upper valve 124 controls input pipe 123 whichthen leads into the auxiliary drain 120 (i.e., condensate collectionarea) via coupling 128. As shown in FIG. 1, a lower drainage valve 144which, when opened, provides for drainage from the auxiliary drain 120through drain pipe 146. The drain pipe 146 may include a cap 148, whichcan be, for example, secured or screwed (i.e., threaded cap) or otherconnection method onto the end of the drain pipe 146.

In accordance with an exemplary embodiment, the input pipe 123 travelsinto the housing 110 via pass-through 121, which can be sealed toprevent nuisances such as bees or other unwanted intruders fromentering. There may or may not be a seal, a seal may be water resistantor proofed, other protections as known in the art, etc. may be used asdesired in various embodiments. Drain pipe 146 travels throughpass-through 147 which is also sealed in a similar manner topass-through 121. The cap 148 can be removed to drain the auxiliarydrain 120, desirably in an appropriate procedure that maintainspressurization, as is described, for example, in National FirePrevention Association (NFPA) 25 guidelines.

In accordance with an embodiment, the cabinet 102 can include athermometer 136 configured to display the temperature inside the housing110 of the cabinet 102 though an external dial 137 (FIG. 2B) on the door112. In various embodiments that temperature may be monitored and analarm be set to provide warning if the inside temperature fell below apredetermined level. That alarm may be local and/or be sent to a centrallocation as desired. It should be noted that, although exemplaryembodiments contain an auxiliary drain 120, it might be desired in otherembodiments to provide a retrofit embodiment to install around anexisting auxiliary drain 120.

In accordance with an exemplary embodiment, the auxiliary drain and/orcondensate collection system 100 can include, for example, a mechanicalversion (FIGS. 1-2C), which uses a Y-strainer 160 and a drain trap 140.As shown in FIG. 1, the drain trap 140 can be plumbed in parallel to themain collection pipe (i.e., main condensate collection pipe) 122 of theauxiliary drain 120 via a side port 162 on the main collection pipe 122.As water condensation makes its way through the fire system and down tothe auxiliary drain 120, the level of condensation will increase untilit reaches the side port 162 at which time the condensation will beginto spill over into the drain trap 140 after first passing through theY-strainer 160. In accordance with an embodiment, the Y-strainer 160offers a layer of protection to help prevent suspended debris in thecondensate from reaching and potentially clogging the drain trap 140.When enough condensation accumulates in the drain trap 140 andY-strainer 160, a float inside the drain trap 140 will lift off of itsseat allowing the accumulated water to exit out of the cabinet 102. Whenenough water drains from the drain trap 140, the float will reseatclosing off the exit path and preventing the dry systems pressurized airfrom escaping the system. In accordance with exemplary embodiment, theamount of condensation being drained by the system 100 should berelatively minimal and, a secondary drain line 150 connected to a lowerportion 141 of the drain trap 140 can be used, for example, in the formof flexible tubing or the like.

In accordance with an exemplary embodiment, this process willcontinually repeat as more condensate makes its way to the drain trap140 or until the main collection pipe 122 of the auxiliary drain 120 ismanually drained of condensate through the main drain 146. Since thedrain trap 140 and/or the Y-strainer 160 will maintain a certain amountof accumulated condensation, it can also be of vital importance that thedrain trap 140 also be protected by the insulated and heated cabinet102, or else, the drain trap 140 would be subject to failure as a resultof freezing.

In accordance with an exemplary embodiment, when the auxiliary drain 120is almost completely full, and the drain trap 140 can allow relativelysmall amounts of water to drain from the system 100, a level switch 126,by way of a local buzzer light (i.e. an alarm) 143 can alert the userthat the auxiliary drain 120 needs attention. In accordance with anembodiment, the drain trap 140 can provide a level of security to thesystem 100 that eliminates the need for immediate attention.

In accordance with an aspect, the system 100 can also include a cabinetheater 130 configured to be mounted directly to the main collection pipe122 of the auxiliary drain 120, which can rather easily be installed orremoved because with a bracket design that is not tied to the electricalenclosure. Second, an orientation of the heater 130 can be used tomaximize component life by vertically mounting the heater with a fan ofthe heater blowing upward into cabinet 102. For example, the mountingbracket 131 can improve the orientation of the heater 130 in itsposition to maximize its effectiveness. In accordance with an exemplaryembodiment, the mounting bracket 131 can include a deflector 132, whichdirects the warm air flow coming from the heater 130 onto the maincollection pipe 122. For example, instead of simply warming the airinside of the housing 110 of the cabinet 102, the deflector 132 of themounting bracket 131 focuses the energy (i.e., heat) of the heater 130onto the main collection pipe 122 thereby maximizing the heat transferinto the pipe 122, which can help ensure that the condensate inside ofauxiliary drain pipe 120 will remain liquid even in the coldestclimates.

The cabinet 102 also includes an electrical enclosure 170, whichcontains components for an alarm as well as other components such ascircuit protection, a relay and terminal blocks. For example, a locallight buzzer 143 can extend through recess 142 in the door 112 of thecabinet 102 and provides an audible sound, for example, a buzzer, andlight (i.e., a flashing or solid red light) when the main collectionpipe 122 of the auxiliary drain 120 is full of condensate. In otherembodiments, it should be noted and as was described above, the alarmmay trigger when varying amounts, or any at all, of condensateaccumulates. The electrical enclosure 170 is at least a NEMA 4 enclosurein exemplary embodiments as set forth in the National ElectricalManufacturers Association Standards Publication 250-2003. Conduit (notshown) can provides power to the heater 130 and the local light buzzer143, which in exemplary embodiments is 120V and enters the housing 110through a pass-through (not shown), which can be sealed similarly to theother pass-throughs 121, 147.

In accordance with an exemplary embodiment, the heater 130 can be sizedappropriately, (for example, a 60 Watt (W) heater in tone exemplaryembodiments), for example, to provide the interior of housing 110 withan air temperature of from approximately, for example, 40° F. to 60° F.,which may be set by thermostat, be preset, allow for setting during orafter installation, be set from a central control area, etc.

It should be noted that exemplary embodiments may provide forcentralized control as well, with the alarm settings, drainage, heaterand other components being monitored and/or manipulated from a centrallocation. Exemplary embodiments may include as well a test device toconfirm the alarm and other components are working correctly, which mayas well be local and/or activated and/or monitored from a centrallocation.

FIG. 3 is front view of the cabinet 102 for the auxiliary drain and/orcondensate collecting system 300 with the door open 112 in accordancewith another exemplary embodiment. As shown in FIG. 3, an electricalversion of the system 300 as shown in FIG. 1 is disclosed that includesa programmable logic controller 172 housed within, for example, theelectrical enclosure 170, and a self-draining apparatus comprising anautomatic drain 180 and a level switch within auxiliary drain 120 asdisclosed above. In accordance with an exemplary embodiment, theautomatic drain 180 can include one or more motorized ball valvesconfigured to perform automated draining of an auxiliary drain 120. Asdisclosed, condensate will slowly accumulate in the main collection pipe122 of the auxiliary drain 120. Eventually, the condensate level willreach the level switch 126 at the top of the main collection pipe 122.When this happens, the float will lift as before but, in this case, thelevel switch 126 will close a set of electrical contacts which signalthe programmable logic controller 172 that the main collection pipe 122is full, which will start the automatic draining cycle of the system300, for example, with the automatic drain 180. In accordance with anexemplary embodiment, the programmable logic controller 172 sequencingcan help ensure every valve motion has either reached a fully closed oropen position before continuing to the next step. While conducting thedrain cycle, the programmable logic controller 172 can also activate alocal light buzzer 143 (i.e., an alarm), and closes a pair of troublecontacts which signal a remote panel that the cabinet 102 is executingan automatic drain.

In accordance with an exemplary embodiment, once the drain cycle hassuccessfully completed, the local light buzzer 143 turns off and thetrouble contacts open. In order to also provide an indication that anautomatic drain cycle has occurred, one of the electrical enclosure'scover lamps 174 can be configured to flash until the system 300 ismanually reset. If, however, the cycle does not successfully complete,the local light buzzer 143 will continue to alarm and the troublecontacts will remain closed. Depending on the anomaly, certain lamps174, 175, for, example, on the cover of the electrical enclosure 170 canflash to provide an indication as to the source of the issue.

The programmable logic controller 172 can also offers other, forexample, a semi-automatic drain cycle, a drain override cycle and heatermonitor. For example, if the end user wishes to drain condensate fromthe auxiliary drain 120 before the main collection pipe 122 is full, theuser can simply press a drain pushbutton 176 provided for example on thecover of the electrical enclosure 170. The programmable logic controller172 can then execute an on demand drain cycle to safely empty itscontents without any risk of accidentally opening or closing the valvesin the wrong order. Therefore, accidentally tripping the sprinklersystem can be prevented even for the most unskilled operator.

In addition, there may be an occasional need to simultaneously open botha system and drain valves, such as when the sprinkler system is beingdepressurized for service. In accordance with an embodiment, theprogrammable logic controller 172 can be configured to execute thisdrain override cycle when both cover pushbuttons 176, 178 (i.e., drainvalve pushbutton 176 and drain system pushbutton 178) are simultaneouslypressed and held, for example, for approximately two (2) seconds to four(4) seconds, perhaps more optimally, for example, for approximatelythree (3) seconds. Additionally, instead of a relay timer, theprogrammable logic controller 172 can be coded to activate the locallight buzzer 143 and close the trouble contacts when the heater 130 hasbeen continuously active for more than a few hours.

FIG. 4 is an illustration of a dry pipe sprinkler system 400 inaccordance with an embodiment. The dry pipe sprinkler system 400typically includes a network of pipes 410 which are in fluidcommunication with sprinkler heads (not shown). The network of pipes 410is filled with a pressurized gas, e.g., air or nitrogen. As disclosedherein, the dry pipe sprinkler system 400 can be used, for example, inparking garages, manufacturing facilities, self-storage facilities, homecenter garden area and other similar location. As shown in FIG. 4, thedry pipe sprinkler system 400 can include one or more auxiliary drainand/or condensate collecting systems 100 (420, 422, 424, 426, 428, 430)as disclosed herein.

FIGS. 5A and 5B are a front view and a side view, respectively of anauxiliary drain 500 with a flow restrictor valve 600 in accordance withan exemplary embodiment. As shown in FIGS. 5A and 5B, a pair of valves510, 520, for example, a first valve 510 (i.e., a system valve) and asecond valve 520 (i.e., a drain valve) can be provided at an upperportion of the auxiliary drain 500 and at a lower portion of theauxiliary drain 500, respectively. The first or system valve 510comprises an inlet which communicates with the flow restrictor valve 600and via the flow restrictor valve 600, the pipes of the dry pipe system400 (FIG. 4).

In accordance with an embodiment, the first valve 510 can include avalve actuator 512 such as a lever or T-handle, which is arranged torotate about an axis. For example, the first valve 510 can be aquarter-turn valve with the valve fully open when the valve actuator isaligned with a longitudinal axis of the first valve 510 and with thevalve fully closed when the valve actuator has been rotated 90 degreesto position the valve actuator generally perpendicular to thelongitudinal axis of the first valve 510.

In accordance with an exemplary embodiment, the second valve 520similarly has an inlet in communication with the auxiliary drain 500 andan outlet. The second valve 520, like the first valve 510, has a valveactuator 522 such as a lever or T-handle which is arranged to rotateabout an axis. In an exemplary embodiment, the valve actuator 522extends a predetermined distance from the axis. The second valve 520 maybe a quarter-turn valve with the valve fully open when the valveactuator 522 is aligned with a longitudinal axis of the second valve 520from the inlet to the outlet and with the valve fully closed when thevalve actuator has been rotated 90 degrees to position the valveactuator generally perpendicular to the longitudinal axis of the secondvalve 520.

FIG. 6 is a cross sectional view of the first valve 510 and the flowrestrictor valve 600 along the line VI-VI in FIG. 5A. As shown in FIG.6, the flow restrictor valve 600 has a housing 602 and includes an inlet630 and an outlet 640. The housing 602 can have, for example, acylindrical shape or a hexagonal shape. The inlet 630 may include aseries of internal (e.g., female) threads 632 configured to receive apipe end (not shown) from a pipe of dry pipe system 400. The outlet 640includes a series of external (e.g., male) threads 642 configured to bethreaded into internal threads (e.g., female) threads of the first valve510. The inlet 630 being in fluid communication with the outlet 640 viaan interior portion 634 of the cylindrical housing 602.

As shown in FIG. 6, a plunger (or shuttle) 610 is held in the openposition by a compression spring 620 that allows the flow of a liquid orgas to pass through the valve 600 under typical operating conditions. Inaccordance with an exemplary embodiment, the typical flow rate of theliquid or gas in the system 400 is slow enough that it does not haveenough velocity to overcome the spring's force so the plunger 610remains in the open position as shown in FIG. 6. If there is a break orunintended opening in the plumbing downstream of the flow restrictorvalve 600, the flow rate and velocity will suddenly increase. This largeincrease in velocity will result in a large increase in the forceagainst the plunger 610, overcoming the resistance of the spring 620causing the plunger 610 to snap closed against a seat 650, for example,within a fraction of a second. Once closed the plunger 610 can be heldin the closed position by the now static pressure of the upstream liquidor gas.

FIG. 7A is a top view of a flow restrictor valve 600 in accordance withan embodiment. As shown in FIG. 7A, the flow restrictor valve 600 has aninlet 630 with a series of internal (e.g., female) threads.

FIG. 7B is a side view of the flow restrictor valve 600. As shown inFIG. 7B, the flow restrictor valve 600 has a housing 602 and a series ofexternal (e.g., male) threads 642 on the outlet end 640 of the valve600. In accordance with an exemplary embodiment, the external threads642 are, for example, 1″ NPT (National Pipe Thread).

FIG. 7C is a bottom view of the flow restrictor valve 600. As shown inFIG. 7C, the flow restrictor valve 600 allows condensate and/or water toflow through a plurality of openings 633 within the retaining member 603to the outlet 640 of the flow restrictor valve 600.

FIG. 8 is a cross sectional view of the flow restrictor valve 600 alongthe line VIII-VIII in FIG. 7B in the open position. The flow restrictorvalve 600 includes an inlet 630 in fluid communication with an outlet640. The interior portion 634 of the valve 600 includes a retaining ring612, an accelerator 608, a spacer 606, an O-ring 614, the plunger 610, apin 604, and the spring 620. The retaining ring 612 is located on aninner surface of the valve 600 and configured to retain the accelerator608, the spacer 606, the O-ring 614, the plunger 610 and the spring 620within the interior portion 634 of the valve 600. The spacer 606 isarranged between a lower edge (i.e., slightly smaller diameterpassageway 607) of the accelerator 608 and an upper edge of a retainingmember 603 configured to house the plunger 610 and the compressionspring 620.

The retaining member 603 includes an inner annular side wall 635 and abase portion 637 having a plurality of openings 633 (FIG. 7C) configuredto retain the spring 620 and allow condensate and/or water to reach theoutlet 640. The retaining member 603 also include an inner annularprotrusion 639, which extends upward from the base portion 637 andprovides a platform 641 for the spring 620 to be compressed downwardwhen the flow restrictor valve 600 is in a closed portion.

In accordance with an exemplary embodiment, the spring 620 can beenclosed in a protective shroud 622 formed by the downstream side 613 ofthe plunger 610. Any contaminated liquid will move past this locationand be prevented from depositing on the spring 620 because it is not inthe condensate's flow path. In addition, the shroud 622 will naturallyform a protective pocket of captured air which is an important featurebecause an auxiliary drain 120 may be allowed to overfill due to lack ofmaintenance. If the liquid level reaches the flow restrictor valve 600,the spring 620 will remain dry because of this protective air pocket.

FIG. 9 is a cross sectional view of the flow restrictor valve 600 alongthe line IX-IX in FIG. 7A in the closed position. As shown in FIG. 9,the accelerator 608 is an annular member having a slightly smallerdiameter passageway 607 on a lower portion of the annular member andimmediately upstream of the plunger 610. The accelerator 608 has anupper diameter 609 that is greater than the lower diameter passageway607 to accelerate a flow of water towards the plunger 610 to help ensurethat the velocity immediately before the plunger 610 is high enough toguaranty the force generated is enough to close the plunger 610. Inaccordance with an exemplary embodiment, any water moving toward theflow restrictor valve 600 during a rupture (or fully open AD) will beforced through this slightly restricted passageway 607 and naturallyaccelerate to the point of generating enough force to close the plunger610. While measurably smaller than the inside diameter of the pipe, thepassageway 607 of the accelerator 608 is still large enough that it willnot clog with condensate debris and since there are no sprinklersdownstream of the auxiliary drain 120, such that a reduced inside pipediameter does not compromise the system 400.

In accordance with an exemplary embodiment, the plunger 610 includes anupper platform 621 having a relatively flat upper surface, an annularside wall 623 having a relatively vertical surface parallel with theflow through the valve, a tapered side wall 625, and an annular lowerportion 627 having a hollow inner portion 629, which is configured toreceive and form the protective shroud 622 for the spring 620.

As previously mentioned, the condensate which exists in a dry sprinklersystem will likely contain corrosion and other clogging debris, whichmay necessitate the need for a relatively larger passageways through theflow restrictor valve 600. In addition, the failure created by a freezeand break may not be as large as an open valve and it may not be a majorrupture such as would be created from a severed natural gas line. Inboth cases there is a risk of not having enough velocity when needed toovercome the spring's force and close the flow restrictor valve 600. Inaccordance with an exemplary embodiment, a lighter compression spring620, for example, which needs less force to close the plunger 610 can beused.

FIG. 10 is a detailed view of the section X of FIG. 9. As shown in FIG.10, a sealing interface 660 between the plunger 610 and a seat 650 ofthe retaining member 603 is disclosed that is designed to be an edgecontact. Instead of having the same tapered angle, the angle between alower surface 672 of the plunger 610 and an upper edge 662 of theretaining member 603 can differ, for example, by a few degrees, forexample, 1 degrees to 10 degrees, and more perhaps more optimally, 2degrees to 5 degrees. In accordance with an embodiment, a taper 664 ofthe seat 650 of the retaining member 603 is at a steeper angle (i.e.,greater angle) than a taper 674 of the plunger 610. In accordance withan exemplary embodiment, the difference in tapers 664, 674 of the seat650 of the retaining member 603 and the plunger 610 can cause thesealing force to be focused on an outer edge portion 676 of the plunger610 instead of distributing it across the entire sealing face, which notonly creates a consistent level of contact force, but it also reducesthe likelihood of contamination keeping the two parts from touching eachother when there is a buildup on the face of the seat. In accordancewith an exemplary embodiment, for example, the edge contact will knifethrough this debris because the force is focused on a relativelysignificantly smaller area.

In accordance with an exemplary embodiment, a consistent level ofsealing can be beneficial, however, a perfect one may not desirable. Forexample, there may be several auxiliary drains 120 in a dry system, andit may not be obvious as to which auxiliary drain 120 has beencompromised by a freeze and break. While the flow restrictor valve 600is designed to prevent the catastrophe associated with a wide-openauxiliary drain failure, a small flow of water from the broken auxiliarydrain 120 can provide a relatively easy indication as to which locationhas been compromised. In addition, even after the water supply has beenturned off and the system depressurized, the column of water above theflow restrictor valve 600 must be drained down for the plunger 610 toreopen. A minimal and controlled amount of water flowing passed the flowrestrictor valve 600 will slowly remove the water weight above it andeventually cause the valve's plunger 610 to reopen. For these reasonsthe design includes one or more notches 670, for example, two or morenotches 670 cut into the outer edge (i.e., outer sealing edge) 671 ofthe plunger 610. The size of the notches 670, along with the differencein taper of the plunger 610 to seat 650, creates a consistent and smallrelief path for the water to move passed the flow restrictor valve 600in a predictable manner. In accordance with an embodiment, the one ormore notches 670 may be a relatively flat surface on the circumferenceof the plunger 610. Additionally, the use of notches 670 may be moreadvantageous, for example, than a small diameter bleed hole in theplunger 610, since a rather small hole can become clogged rather easilyby condensate debris.

The principles, exemplary embodiments and mode of operation of thepresent invention have been described in the foregoing specification.However, the invention which is intended to be protected is not to beconstrued as limited to the particular embodiments disclosed. Theembodiments are therefore to be regarded as illustrative rather than asrestrictive. Variations and changes may be made without departing fromthe spirit of the present invention. Accordingly, it is expresslyintended that all such equivalents, variations and changes which fallwithin the spirit and scope of the present invention as defined in theclaims be embraced thereby.

What is claimed is:
 1. A system for maintaining the integrity of a drypipe sprinkler system, comprising: an auxiliary drain including a maincollection pipe; a heater having a bracket configured to attach theheater to the main collection pipe of the auxiliary drain, the bracketincluding a deflector configured to direct heat from the heater onto themain collection pipe; and a self-draining apparatus configured toreceive excess water from the auxiliary drain.
 2. The system accordingto claim 1, wherein the self-draining apparatus comprises: a Y-strainerin communication with a side port of an upper portion of the auxiliarydrain, the Y-strainer configure to receive the excess water from themain collection pipe of the auxiliary drain; a drain trap arranged inparallel to the auxiliary drain and in communication with theY-strainer, the drain trap having a float configured to release waterfrom the drain trap upon the float lifting off a seat within the draintrap; and a drain tube extending from a lower portion of the drain trapand configured to receive the water released from the drain trap.
 3. Thesystem according to claim 1, wherein the self-draining apparatuscomprises: a programmable logic controller configured to receive asignal from a level switch within the auxiliary drain when the excesswater is detected in the main collection pipe of the auxiliary drain; anautomatic drain arranged on a lower portion of the auxiliary drain andconfigured to receive a signal from the programmable logic controller torelease at least a portion of the excess water within the auxiliarydrain though a drain pipe connected to the automatic drain.
 4. Thesystem according to claim 3, wherein the automatic drain comprises oneor more motorized ball valves configured to release water from the maincollection pipe of the auxiliary drain.
 5. The system according to claim1, further comprising; an input pipe; a first valve configured tocontrol fluid passage from the input pipe into the main collection pipeof the auxiliary drain; a second valve configured to control fluidpassage from the main collection pipe of the auxiliary drain into adrain pipe; and an insulated housing with a door configured to provide aheat controlled environment, and wherein the auxiliary drain, theheater, and the self-draining apparatus are located within the housing.6. The system according to claim 1, further comprising: an alarmconfigured to provide a warning when the auxiliary drain retains apredetermined amount of condensate.
 7. The system according to claim 5,wherein the insulated housing further comprises a weather resistantinsulated housing.
 8. The system according to claim 5, wherein theinsulated housing further comprises a locking door.
 9. The systemaccording to claim 1, wherein the heater is thermostatically controlled.10. The system according to claim 1, further comprising: a flowrestrictor valve, the flow restrictor valve including a plungerconfigured to be held in an open position by a compression spring, theopen position configured to allow a liquid or gas to flow through theflow restrictor valve and a closed position in which a flow of theliquid or gas generates a velocity sufficient to cause the compressionspring to compress and engage an outer edge of the plunger with a seatof a retaining member to prevent the flow of the liquid or gas throughthe flow restrictor valve.
 11. The system according to claim 10, whereinthe flow restrictor valve is arranged on an upstream side of theauxiliary drain.
 12. The system according to claim 10, wherein theplunger includes one or more notches in an outer edge to allow at leasta portion of the gas or liquid to flow through the flow restrictor valvewhen the flow restrictor valve is in the closed position; and anacceleration configured to increase the flow of the gas or liquid ontothe plunger with a reduced diameter passageway arranged immediatelyupstream of the plunger.
 13. The system according to claim 10, wherein adownstream portion of the plunger forms a protective shroud configuredto protect the compression spring.
 14. A flow restrictor valve, the flowrestrictor valve comprising: a plunger configured to be held in an openposition by a compression spring, the open position configured to allowa liquid or gas to flow through the flow restrictor valve and a closedposition in which a flow of the liquid or gas generates a velocitysufficient to cause the compression spring to compress and engage anouter edge of the plunger with a seat of a retaining member to preventthe flow of the liquid or gas through the flow restrictor valve.
 15. Theflow restrictor valve according to claim 14, wherein the plungerincludes one or more notches in an outer edge to allow at least aportion of the gas or liquid to flow through the flow restrictor valvewhen the flow restrictor valve is in the closed position.
 16. The flowrestrictor valve according to claim 14, wherein the flow restrictorvalve includes an acceleration configured to increase the flow of thegas or liquid onto the plunger with a reduced diameter passagewayarranged immediately upstream of the plunger; and the outer edge of theplunger including a tapered edge and the seat of the retaining memberhas a tapered edge, and wherein an angle of the tapered edge of theplunger is different than an angle of the tapered edge of the seat ofthe retaining member.
 17. The flow restrictor valve according to claim14, wherein a downstream portion of the plunger forms a protectiveshroud configured to protect the compression spring.
 18. A method formaintaining the integrity of a dry pipe sprinkler system, comprising:providing an auxiliary drain including a main collection pipe; attachinga heater having a bracket to the main collection pipe of the auxiliarydrain, the bracket including a deflector configured to direct heat fromthe heater onto the main collection pipe; and releasing excess waterfrom the auxiliary drain with a self-draining apparatus, theself-draining apparatus configured to receive the excess water from theauxiliary drain.
 19. The method according to claim 18, wherein theself-draining apparatus includes a drain trap arranged in parallel tothe auxiliary drain and in communication with the Y-strainer, the draintrap having a float configured to release water from the drain trap uponthe float lifting off a seat within the drain trap, and a drain tubeextending from a lower portion of the drain trap and configured toreceive the water released from the drain trap, the method furthercomprising: directing the excess water from the main collection pipe ofthe auxiliary drain through the Y-strainer into the drain trap;directing the excess water through the drain trap into the drain tube;and releasing the excess water from the dry pipe sprinkler system viathe drain tube.
 20. The method according to claim 18, wherein theself-draining apparatus includes a programmable logic controllerconfigured to receive a signal from a level switch within the auxiliarydrain when the excess water is detected in the main collection pipe ofthe auxiliary drain and an automatic drain arranged on a lower portionof the auxiliary drain and configured to receive a signal from theprogrammable logic controller to release at least a portion of theexcess water within the auxiliary drain though a drain pipe connected tothe automatic drain.